Process and apparatus for producing sheet glass



J. L. DRAKE March 8, 1932.

PROCESS AND APPARATUS FOR PRODUCING SHEET GLASS Filed June 8. 1928 2 Sheets-Sheet March 8, 1932. L. DRAKE 1,848,111

PROOESSVAND APPARATUS FOR PRODUCING SHEET GLASS Filed June 8. 1928 2 Sheets-Sheet 2 jwuento'o do/m L. Drake.

f5? MW Patented Mar. 8,t193 2 r JOHN L. DRA E, or TOLEDO, OH'IO, ssI'GNoR-ro LrnnnY- ownns ronn GLess omma; 0 .TOLEDO, 01110, Aooaronerronon OHIO:

PROCESS em) APPARATUS Fora, PRODU ING" SHEET GLASS lipplic ation filed June s, 1925; Serial no. 1283354.

The present invention relates to a process I V I through the construction; illustrated in Fig. 2..

and apparatus for producing sheet glass. 7

1 An important object of the invention is to provide a process andan apparatus for pro-- diicing sheetglass wherein a sheet is formed from amass of molten glassand deposited upon: a 'movable' conveyor created from one or more endless belt forinatiohathe speed of the sheet being reduced while on :saiol'jc0n veyor, after which the sheetis fed intoand through an annealing leer.

. Another object of'thei ventionj is't o; pro

7 vi'de Ineansfor reducing a pott'uLofInolten glass to sheet form, the sheetbeing passed upon a conveyor'whose speed is approximately the same asthespeed: at which the sheet is formed, the speed of the conveyorvbeing reduced after the entire sheet length has been arrangedthereon, after which the sheet is'ife'd into and through an annealing leer-at :a speed substantially thesame, as .the 'redu ced speed of the conveyor.

' A still further and np'ortant obie'ctof'the invention is to provide means wherein a mass of Inolte-n'glass is reduced'to sheet form at one speed, then while the entire sheet is supported on a conveyor the speed thereof is reduced, the sheet being preferably prote'ctech against undue chilling while on said conveyor, after which thesheet is passed through an anneal- 7 ing leer at substantiallyv one speed f o n end of the leer to the other. 7 i

Other objects and advantages ofthe inven tionwill become more apparent during the course of" the following description when taken in connection with the accompanying V drawings. Y

In the drawings wherein like numerals are I employed; to designate like. parts throughout thesamea ,Fig. 1 is a diagrammatic vertical longitudinal section through an apparatus e mbodying my improvedconstruction,1 Fig. 2- is asim' ilar view showin'ga slightly modified form of construction,

Fig. 3 is afragmentary-vertical sectional view; showinga detail of one type" of? conveyor, Fig. 4 isfa-fragmentary top planview of V y y 3 theilength of the conveyor-.16 iSS l h that the said conveyor, and

-; Fig. 5 is a vertical transverse section .The present: invention Irelates, more .par

ticularlyqto an intermittent .pro'cessotpro ducingf sheet glass, and it .is preferred that .pot :gla ss be used in the formation' oflthe sheet, the term ;.p'ot glass being well under stoodin the art. 'Sufli'ce is torsay that such I high quality;

glass is desirable because. of the. generally.

Referring to Fig.1, the numeral 10 desig'a nates potshown in dotted line's'infa tipped position, which is the'position" assumedjwhen" to con-tainfanentire,potful of molten glass.

Because of the fine quality of glass which can] be, produced 1m pot,: it is preterredthat the I molten glass be created-in thisma'nlier, but e .70.

obviously charges ,of-glass can be: supplied to the 7 container 11' from a tank furnace or the like, if desired. Associa'ted with the sup port 'or'container llfis apair of sheet forming same in a. a flat'surfaceg -It is preferred that the sheet'of glass the glass is poured onto the supportingmem- 1 her ,11, which member is preferably of 'a-size gee rolls 12, arranged to createla. sheet forming .rai1s18 may beplaced beneath the upperihorit r a V zontal r n f h nveyor 16 to suppg t the P hat. the sheet rest up'pn produced'at a relatively high rate of. speed; so

that'the molten mass 13 will notbecome .un-

duly chilled, and to leave the glass in contact r with the foriningrollsja relatively short time. During the formation of the sheet, therefore, the. conveyor '16 is operated ata speed substantially: identical with the-peripheral speed i as the movement ofthesheetld. jFurthen of therolls 12, which of course is the :same.

entire sheet formed from the mass of molten glass'13 can be supported at one time on the upper horizontal run of the conveyor. In one embodiment of the invention, as soon as the entire sheet is resting on the conveyor 16, the conveyor is stopped. It is then started again at a relatively slower speed and preferably at a speed similar to the speed of the leer rolls 19 arranged within the annealing leer 20, which speed is relatively much less than the speed at which the sheet is formed. It is not desirable to move the sheet as rapidly during the annealing thereof as during the forming because of the unnecessarily long leer thus required. Upon restarting of the conveyor 16, the sheetmay be passed over a roll 21 and then through the annealing leer, which is preferably provided at its intake end with temperature control means 22 for the purpose ofassisting in obtaining proper annealing It may also be desirable to elevate the temperature of the glass sheet at the in;

take end of the leerto atemperatureabove the critical annealing rangeof glass, thus relieving or removing strains introduced in the glass wlienfforining it into asheet, etc. The numeral 23 designatesthe sheet [as it passes from the cold end of the'leer. The .conveyor'lo, shown in Fig. 1, may be formed from asbestos, a non-corrosive metal, or the like. Tov prevent too rapid chilling of the glass sheet while on the conveyor'l-G, temperature control means 24 are provided, and 'as shown some offthe means 24 are adapted to act in close proximity to the sheet, while others are positioned to act upon the lower run of the conveyor.

In Fig. 2 a modified construction is illustrated showing a plurality of conveyors 25, so that instead of having-a single conveyor as in Fig. 1, a plurality of conveyors are arranged to support the sheet 26 immediately after it has been formed by the rolling mechanism 27. It is preferred, however, thatthe conveyors 25 be drivenas a unit and their speed of movement synchronized. As in the case'of the single conveyor, the conveyors 25 are, during the sheet forming stage, moved 'at the same speed as the peripheral speed of the forming rolls. 'Ih'en, when'the entire sheet is bein sun aorted upon the 'con-' veyors, they are stopped and then restarted so that the sheet movesforward at substantially the same speed as that of the leerrolls 28. 'To protect the' sheet after it has been slowed down and before it enters the leer, a vertically adjustablehood 29 may be used, illustrated diagrammatically as being supported by an adjustablecable 30. During the rolling of theglass into sheet form, the hood is arranged in an elevated position as indicated in dotted lines in Fig. 2. As soon asthe entire sheetis supported'upon the conveyors 25 and its speed has been reduced, the

hood is loweredwhere'by-to prevent chilling of the glass as it passes relatively slowly into the annealing leer 31. After the entire sheet has passed into the leer 31 from the conveyor, the hood is raised and thereby sheetcan be rolled relatively fast and annealed slowly and yet cause no piling up of the sheets in the annealing leer.

In Fig. 3 is illustrated a modified form of conveyor which comprises a plurality of links 32 pivotally associated by means of the cross rods 33. As shown in Fig. 4, the shape of the links 32 is preferably such that sol-id top table is formed. The term solid top is here used to designate a table substantially free from openings or portions where-the plastic sheet can sag. A drum '34 is provided to drive the conveyor, mainly by frictional contact. Of course, the conveyor can be formed in many otherways, and therefore the invention is not to be construed as limited to any of the types illustrated.

In operation the molten glass is supplied to present process is intermittent. By proper, timing of the rolling operation, therefore, a

the sheet forming pass where it: is reduced 7 into a sheet of substantially uniform and predetermined thickness, the length of the sheet formed being dependent upon the quantity of glass rolled and the thickness and width of the sheet. In any event, the conveyors are made sufiiciently long to support the entire sheet at one time. The molten glass is rolled into a sheet at a relatively high rate of speed, and during the, rollingof the sheet, the conveyor is operated at the same speed as the sheet forming'mechanism. As soon as the entire sheet is supported upon the conveyor, it is stopped and then started at a relatively slower speed than the forming speed so that the sheet is fed into the leer at the desired annealing speed. It is preferred that the sheet move at a uniform rate ofspeed throughout the entire length of the leer.

In another embodiment of the invention. the conveyor is operated a little difierently, in that'instead of stopping the same as the entire sheet rests thereupon, the speed can be quickly reduced to the annealing speed before the sheet starts to enter the leer. In any event,the speed of the sheet is completely changed between the sheet forming apparatus and the annealing leer. Heating means, either with or without a hood, can be used to protect the sheet while it passes from the sheet forming mechanism tethe annealing leer.

No particular type'of drive has been shown for the forming mechanism and the conveyor,

as any suitable type will be satisfactory.

It; is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims. 7 i 7 I claim: r y

1. The process of producing sheet glass;

consisting in forming a sheet of glass ata relatively high rate of speed, supporting and carrying the sheet forwardly upon a movable substantially unbroken surface at the same. speed'as thatof the forming means, then when the entire sheet is positioned on the surface, stopping said surface, and then starting' the surface again at a relatively slow speed and passing the sheet through an annealing leer at a speed similar to the relatively slow speed ofthe surface. Y V 1 v V 2. The process of producing sheet glass I which consists in forming the sheet at a relasaid surface, in then resuming movement of p the supporting surface to carry the sheet'forwardly at a relatively slower speed, and'in passing the sheet forwardly at such speed tively high rate of speed, supporting and carrying the sheet forwardly during formation thereof upon a. movable substantially unbroken surface, stopping. the movement of said surface afterthe sheet has been entirely Q 7 i received thereupon whereby to arrest the forward travel ofthe sheet and facilitateflattening thereof during its period of rest upon into and through an annealing leer.

' 3. The process of producing v sheet glass consisting in forming the sheet at a'relatively high rate ofspeeda passing the sheet forwardly in a substantially straight line from its 7 point of formation at a relatively low rate of a speed into and through an annealing leer, in a temporarily supporting the sheet between the point of formation and the exit end of the annealing leer upon a substantially unbroken surface, in receiving the sheet upon said surface while travelling at its speed of formation. in arresting the forward movement of the sheet while upon said surface to facilitate flattening thereof and in then resuming forward travel of the sheet and delivering it from said surface ata relatively slower speed. Signed to Toledo, in the county of Lucas and State of Ohio, this 6th day of June. 1928. r

JOHN L. DRAKE. 

